Randomized dose-response analysis of mitomycin-C to prevent haze after photorefractive keratectomy for high myopia

Abstract

To evaluate the safety and efficacy of mitomycin-C (MMC) 0.01% (0.1 mg/mL) in preventing haze formation after wavefront-guided photorefractive keratectomy (PRK) for higher myopia at 3 exposures. United States Navy Refractive Surgery Center, San Diego, California, USA. Double-masked randomized prospective trial. Sixty-, 30-, and 15-second exposures of MMC 0.01% were compared in wavefront-guided PRK for higher myopia. One eye received MMC (surgical sponge) and the other a placebo. All eyes received a 4-month tapering postoperative topical steroid regimen. Endothelial cell densities, haze scores, high- and low-contrast acuities, and manifest refraction were measured preoperatively and 1, 3, 6, and 12 months postoperatively. Outcomes were analyzed as repeated measures over time. The mean preoperative manifest refraction spherical equivalent was -5.98 diopters (D) (range -4.4 to -8.0 D). No eye developed more than trace haze. There was a significant difference in haze scores between MMC-treated eyes and untreated eyes at 1 and 3 months (P=.034) but no difference at 6 and 12 months. Endothelial cell densities decreased in the treated eyes and untreated eyes at all 3 exposures at 1 month but returned to baseline by 6 months. There was no difference in acuities or refractions with or without MMC. Mitomycin-C may not be needed to prevent haze after modern PRK with a 4-month steroid taper. There was no clinically significant difference in haze formation between MMC eyes and control eyes at the concentration and exposures used.